The present invention relates to a new and distinct cultivar of hydrangea that is grown for use as an indoor floral potted plant and an outdoor ornamental flowering shrub. The new cultivar is known botanically as Hydrangea macrophylla and will be referred to hereinafter by the cultivar name ‘RIE 05’.
‘RIE 05’ resulted from a breeding program that was conducted by the inventor at the inventor's nursery in Kyoto, Japan and began in 1990. The purpose of the breeding program was to produce new varieties of floral potted hydrangeas the exhibit new and unique flowers and flower color.
Between May 1990 and May 1993 the inventor assembled a collection of unnamed and unreleased hybrids from a sequence of deliberate pollinations involving the following cultivars, all unpatented, and available in commerce in Japan: Hydrangea macrophylla ‘Otafuku’, Hydrangea macrophylla, ‘Yamaajisai’, and Hydrangea macrophylla ‘Fijinishiritaki’. The inventor did not record which variety was used as male parent and which as female parent. In May 1993, the inventor carried out a deliberate pollination between one unnamed plant from the inventor's collection as female parent and the variety Hydrangea macrophylla ‘Sumidanohanabi’ (unpatented) as male parent.
The pollination described above produced thirty-five individual varieties, which the inventor considered novel and unusual. One of these individual varieties was selected by the inventor in June 1994 and is the subject of the present invention, ‘RIE 05’.
‘RIE 05’ is a deciduous shrub that exhibits large dark grey-green leaves and individual flowers that range in color from yellow-green to light and dark pink. Selection was based on the distinguishing characteristics of flowers, flower color, and inflorescence development. ‘RIE 05’ most resembles the “mophead” type of hydrangea. “Mophead” type hydrangeas produce showy sterile flowers along the outside of the inflorescence, and small inner flowers that are fertile flowers. However, ‘RIE 05’ is different in that there are no fertile flowers in the inflorescence which consists of sterile flowers only. ‘RIE 05’ is distinguishable from the parent plants by flower color, and unique inflorescence development, which produces an average of 270 sterile flowers per inflorescence. It is also distinguished by the darkening of the flower color with age and in that a single plant might have inflorescences of different ages and therefore several shades of colors are displayed simultaneously.
The inventor considers that ‘RIE 05’ is distinct from other varieties of Hydrangea known to the inventor in the following respects:
First, whereas other varieties of Hydrangea in commerce have four petals per floret on a flat, one-dimensional plane, ‘RIE 05’ has two to three layers of petals per floret, creating a double-flower appearance.
Second, whereas many novel varieties have been found in, or brought from, Japan in recent years, none appear to have the combination of uniqueness of flower form as above combined with greater vigor and faster growing to flowering stage which typifies ‘RIE 05’.
Third, the vigor of ‘RIE 05’ is evident in its strong thick stems which do not require staking to support the heavy blooms. ‘RIE 05’, although vigorous, exhibits a shorter internode distance than many other commercial forms of Hydrangea, allowing ‘RIE 05’ to be grown commercially with less or even no application of growth regulating chemical.
‘RIE 05’ was first asexually propagated by the inventor, in the spring of 1995 in a cultivated area of Kyoto, Japan. The method used for asexual propagation was softwood cuttings. The characteristics of the new Hydrangea cultivar named ‘RIE 05’ have been determined stable and are reproduced true to type in successive generations of asexual propagation.